This year’s Fit Family Challenge competitors are smart, savvy, and full of great nutrition-related questions! I just finished a one hour conference call with 10 family finalists from across the U.S. and Hawaii. As part of their challenge to adopt healthy diet and exercise practices, they were asked to send me their most burning nutrition questions. One mom told me that her goal was “to teach her girls how to think critically” about health information. I was so pleased to see those values being promoted that I thought I’d share some of our mythbusting FAQs here on the blog:
1. I live in a community that doesn’t add fluoride to the public water supply. Do my kids need to take fluoride supplements?
Fluoridation of our water supply is considered to be one of the top 10 most effective public health initiatives of the 20th century. Enhancing the natural fluoride content of water results in up to a 60% reduction in tooth decay for kids! The cost to a community of adding fluoride to the water supply is about 50 cents per person per year, so it’s really quite affordable. I’m not sure why your community water hasn’t been fluoridated, but it’s estimated that about 1/3 of Americans still live in communities that haven’t supplemented their water with fluoride (so you’re not alone).
Our teeth use fluoride to strengthen our enamel – and we can get fluoride to our teeth in two ways: 1) from our blood stream (e.g from the water we drink, digest, and absorb) and 2) topically (e.g. from toothpaste). Studies have shown that it’s best to get fluoride via both routes for optimal enamel strength. For children living in areas where the water is not fluoridated, the American Dental Association (ADA) recommends fluoride vitamins until at least age 16. There are two strengths of fluoride vitamins, and the dosage required depends on the fluoride levels in the local water supply (you can ask your local Water Department for that information if you haven’t already). Keep in mind that most children’s permanent teeth (with the exception of “wisdom teeth”) erupt by age 13 – and before that age there is no way to get fluoride to them except via the blood stream. So digesting fluoride (via water or vitamins) is critical to strengthen those teeth that haven’t broken through the gums yet.
For more information about fluoride, see this helpful ADA guide.
2. Should parents be concerned about hormone levels in milk? Is there an advantage to buying organic milk?
All mammals release trace amounts of hormones into their milk. Cow’s milk naturally contains a small amount of bovine somatotropin (bST) which is a protein that is quickly broken down by our stomachs when we drink milk. Some farmers give their cows additional amounts of the hormone to stimulate milk production. This rbST (or BGH) is virtually identical to naturally occurring cow hormones and the decades of research we’ve collected has been reviewed by the FDA (Food and Drug Association), WHO (World Health Organization), NIH (National Institutes of Health), AMA (American Medical Association), and ADA (American Dietetic Organization) – and all agree that rbST is safe for human consumption in the levels it occurs in cow’s milk. Interestingly, studies have shown that milk hormone levels in organic milk is essentially identical to levels in regular milk. There is therefore no advantage in buying organic milk insofar as hormones are concerned.
I believe that cow’s milk is safe and nutritious for kids (so long as they have no milk allergies or lactose intolerances). The milk/hormone scare is kind of an urban legend, so I wouldn’t be too worried about it. Your girls haven’t suffered any harm from drinking regular milk – and it’s great that you all enjoy the skim variety, by the way. Lower calorie options can help you maintain your weight over your lifetime.
For more information about milk and hormones please check out this helpful link full of research resources.
3. Are there lifestyle choices that I can make to reduce my risk of getting cancer? Can vitamins help?
You are right that there are lifestyle choices that can substantially reduce your risk (and your childrens’ risk) of getting cancer. However, there is no way to guarantee that you’ll never get cancer, no matter how carefully you control your diet and lifestyle. Nevertheless it’s an excellent idea to do what we can to reduce our risks. Cancer is actually a complicated collection of different diseases, and so specific behavior changes may reduce the risk of certain cancers but not others. For example, a high fiber diet may reduce the risk of colon cancer, but not skin cancer.
Also note that it’s very hard to prove that any one dietary change (such as consuming a larger amount of one particular vitamin or herb) has a direct impact on cancer risk. What works is sometimes more general (such as avoiding becoming obese). Here are some behavior changes that have been scientifically proven to reduce cancer risks or prevent certain cancers:
1. Smoking cessation
2. Regular use of sunscreen
3. A diet rich in fiber (i.e.lots of fruits and veggies and whole grains)
4. Maintaining a healthy weight
5. Regular exercise
6. HPV vaccines (especially for young girls – can prevent cervical cancer) and hepatitis vaccines (can prevent liver cancer)
7. Drinking very little alcohol (no more than 1 drink/day)
Screening for cancer is also important – because catching a cancer early is often the best way to cure it. The most effective screening tests are:
1. Colonoscopies (for adults over age 50)
2. PAP smears (for sexually active women and women who haven’t had hysterectomies)
3. Physical exams to check for skin cancer, oral cancer, and testicular cancers
Mammograms and prostate blood tests are less effective at catching cancers early, but they are recommended by most medical professional associations.
I recommend reading this page at the National Cancer Institute for more information about avoiding cancer risk factors:
Multivitamins are not recommended for cancer prevention. Although it would seem that vitamins could help reduce the risk of cancer, large studies have shown that they do not reduce the risk of cancer, and may even increase one’s risk (especially vitamin E.) The best source of vitamins is healthy food – and their fiber benefits are excellent as well. For a nice summary of the unhelpfulness of vitamin supplements, please see this ABC News summary of recent research.
Happy Thanksgiving everyone – I thought I’d blog about food today, and to try to persuade you to trade that pumpkin pie for a glass of milk…
I learned some interesting things at the Dairy Science Forum on November 13th in DC. Dr. David McCarron presented some compelling data on the effects of the DASH diet on reducing blood pressure. The DASH diet is fairly high in dairy products (2-4 servings/day), fruits, and vegetables. In comparison with a low-salt diet (which reduces systolic blood pressure by an average of 1 point), the DASH diet can cause an average reduction in systolic blood pressure of ten points. If you have high blood pressure (and your kidneys are functioning normally) you probably shouldn’t worry all that much about the salt. It’s more important to stick with the DASH diet.
I interviewed Dr. McCarron about the role of dairy in blood pressure management. Here’s what he had to say:
Dr. Val: If salt isn’t the real enemy, and dairy can help to reduce blood pressure, why isn’t that message getting out?
Dr. McCarron: We have national nutrition policies in place that are old and out of date. The healthy eating paradigm – low fat, low sugar, low salt – was established 40+ years ago and when new evidence is obtained, it’s really hard to crack through that illusion of knowledge. There is excessive mistrust of new data because of the attitude that if it conflicts with our previous beliefs, it can’t be true. I believe that the Internet will be critical in allowing the evidence to bubble up. For example, a diet rich in dairy food is absolutely associated with a reduction in virtually all chronic medical conditions. We have data to support this for people of all ethnicities and from around the world. I think that consumers are looking for clarity and simplicity in their nutritional advice – and basically they need to know that a healthy diet requires 3-4 servings of dairy and 5-6 servings of fruits and vegetables/day. If you do that alone (along with regular exercise) you’ll be amazed by the results.
Dr. Val: What is the proposed mechanism by which dairy has all these positive effects?
Dr. McCarron: It’s almost impossible to nail down specific mechanisms because milk products contain so many ingredients (electrolytes, key vitamins, bioactive proteins, and essential fatty acids). Trying to understand which piece is impacting very complicated physiological control mechanisms within the body (that have 30-40 different vectors feeding into them) is extremely difficult. In fact, the permeatations make it almost impossible. We can’t come up with the proof that we do for drugs (which contain only one bioactive ingredient). What we do know, though, is that dairy is a vital component for chronic disease reduction and prevention. Unfortunately the policy people say, “you haven’t explained to me how this works, so I’m not going to consider it.”
Dr. Val: But what about the research suggesting that whey protein contains lactokinins that function similarly to ACE inhibitors (a type of blood pressure medicine)?
Dr. McCarron: That’s been known for over a decade. There’s no question that there are small peptides (proteins) in milk that have a positive impact on blood pressure, mood disorders, and weight reduction. The industry doesn’t want to talk about it because it makes milk sound like a drug, which isn’t effective marketing. Also the average consumer doesn’t have enough background to understand what that means (lactokinins have ACE inhibitor-like effects in vivo), so we need to simplify the message and disseminate it via the Internet.
NEJM, 1998 Effects of Dietary Patterns On Blood Pressure
Am J Hyper, 2004 McCarron and Heaney
JAMA, 2002 Pereria et al
Science, 1984, McCarron et al
JAMA, 1996, Bucher et al
I recently discussed the emerging black market for raw (unpasteurized) milk and the FDA’s crackdown on California farmers. Soon after I posted my comments, a reader asked some detailed questions about heat, enzymes, and milk’s nutritional value. At the same time I received an email from the Vice President of Nutrition Affairs-Health Partnerships at the National Dairy Council, offering to connect me with a dairy product scientist to further the discussion. Isn’t it nice when all the stars align correctly?
I just interviewed Gary Rogers, Ph.D., the Editor-In-Chief of the Journal of Dairy Science and Professor of Animal Science and Dairy Extension Leader at the University of Tennessee in Knoxville. You may listen to the podcast, or enjoy my synopsis below:
Dr. Val: What is pasteurization?
Dr. Rogers: Pasteurization is the heating of milk to a specific temperature for a specified period of time to kill harmful bacteria that may be living in the milk.
Dr. Val: Raw milk enthusiasts argue that pasteurization decreases the health benefits of milk. What exactly is lost when milk is pasteurized?
Dr. Rogers: There are really no important changes that occur (from a nutritional standpoint) to milk when it’s pastuerized. Heat treatment is simply used to kill the bacteria that may present a health risk to those of us who consume milk. Research over the years has shown that there are no significant nutritional benefits to raw milk, but there are risks associated with exposure to bacteria.
Dr. Val: Some people say that raw milk is easier to digest than pasteurized milk. Is that primarily a myth?
Dr. Rogers: Yes, that’s a myth. There is no scientific evidence to suggest that raw milk is easier to digest than pasteurized milk. In fact, many people who have digestive difficulty with fluid milk can eat cheese and yogurt without any difficulty.
Dr. Val: I’ve heard some people claim that there are certain beneficial enzymes in raw milk that are destroyed in the pasteurization process. Is there any truth to that?
Dr. Rogers: There are dozens of enzymes in milk, but most of them are proteases that are involved in the break down of milk proteins and fats. While it’s true that heating can destroy some of these enzymes, they really have no role in human digestion. The enzymes are responsible for milk spoilage, so removing them extends the shelf life of the milk.
Dr. Val: Tell me about UHT milk (the boxed milk that is stored at room temperature) – does it differ -nutritionally and chemically - from pasteurized milk?
Dr. Rogers: UHT (or “ultra-high temperature”) milk undergoes a pasteurization process at a much higher temperature than regular milk. This increases its shelf life, but nutritionally and chemically it’s no different from regular pasteurized milk. It contains all the calcium, phosphorus, and protein of regular milk. However, UHT milk does have a different flavor that some Americans don’t like. In Europe, though, they really enjoy the flavor of UHT milk and often prefer to drink it over pasteurized milk. In the U.S. we use it for flavored milk products, and for military personnel who can’t keep their milk refrigerated as easily.
Dr. Val: I think the key confusion that people have here is that they think of heating milk like heating vegetables. We all know that when we boil vegetables for a long time the nutritional value decreases because their vitamins are removed in the water. However, with milk we’re essentially heating it without removing the “water” part.
Dr. Rogers: That’s exactly right. Pasteurization doesn’t add or subtract anything from milk nutritionally, it’s just a heat treatment to destroy bacteria like listeria and salmonella.
Dr. Val: Are US cows exposed to antibiotics and hormones that could find their way into milk?
Dr. Rogers: I know that consumers are very concerned about these issues, but they need to know that every milk tanker is required by law to be tested for antibiotics. There’s a huge incentive for milk producers not to include milk from cows that may have been sick and treated with antibiotics because any tanker that’s found to have any trace of antibiotic in the milk will have its milk discarded. Not only that, but since tankers usually carry milk from multiple producers, one small contribution of contaminated milk will cause all the neigboring farms’ milk to be destroyed. So there’s a lot of peer pressure to keep the milk supply clean. Farmers who contribute milk from cows on antibiotics are fined for the losses of other producers’ milk as well.
As far as “hormones” are concerned, you’re talking about RBST (recombinant bovine growth hormone) to enhance milk production in cows. Although no lab test was ever able to distinguish milk from RBST treated cows from non-treated cows, consumers expressed such concerns about the practice that few milk producers use RBST anymore. I’d say that maybe 10-15% of dairy producers use it, and then it’s not for fluid milk sale, but rather cheese and other dairy products. Those numbers are continuing to decline.
Dr. Val: What does it mean when milk is labeled “organic?” Given the high price of groceries, are there advantages to purchasing organic milk?
Dr. Rogers: I work with both conventional dairy producers and organic dairy producers in my “day job” so I have friends on both sides. As far as nutrition and healthfulness is concerned, organic and conventional milk are equal. The “organic” label has to do with the production practices on the farms that produce the milk, not the properties of the milk itself. On organic farms, they do not use chemical fertilizers or pesticides to raise the crops that they feed to their cows. Some people like the idea of supporting organic farmers and consumers have every right to do that. But both organic milk and conventional milk are safe and equivalent nutritionally.
Milk is heavily regulated and controlled so that even on conventional farms, the pesticides do not get into the milk. All milk is tested for pesticides, and in my experience it has always contained far lower levels than the standard set for safety by the FDA.
Dr. Val: But isn’t it possible that the organic milk might have an even lower level of pesticides in it than conventional milk?
Dr. Rogers: Actually the tests that I’ve seen have not been able to distinguish organic from conventional milk as far as pesticide levels are concerned. However, I haven’t received results from all the organic farms in the U.S. But keep in mind that pesticides exist in such small quantities in milk that usually we can’t even detect them with the most sensitive instruments that we have in the laboratory.
Dr. Val: Is soy milk a good substitute for cow’s milk?
Dr. Rogers: It’s really hard to replicate the nutrition that comes from traditional milk sources. The calcium absorption, amino acids, vitamin, and mineral contents of milk provide a distinct advantage over soy milk, unless you have a specific dairy allergy. In a large recent study on baby formula, for example, there was no advantage to using soy based formulas over cow’s milk. People may prefer to use soy milk for its flavor, or because they support vegetarian food sources. But most soy milk is processed by dairy farms anyway.
*Listen to the interview with Gary Rogers*This post originally appeared on Dr. Val’s blog at RevolutionHealth.com.
I’ve written about raw milk before, but here again we find it making front page news. There has been a recent FDA raw milk crack down in California, and I believe that’s a good thing for public health reasons. Although raw milk enthusiasts ascribe mystical powers to the product (some say its natural microbial flora can cure everything from asthma to autism), I don’t see anything mystical about the pathogens that can grow in room temperature milk: e. coli, salmonella, listeria and even tuberculosis. If you like the taste of raw milk and don’t mind the risks associated with imbibing warm body fluids of manure-encrusted bovines… then go right ahead. But please, don’t put your children at risk.
The New York Times exposed the raw milk counter-culture phenomenon last year. Grocery store milk has been heated and packaged in a nearly sterile fashion so that no harmful bacteria are in it. Farmers collect raw milk from cows, then send it to a processing plant where it’s pasteurized (a heat treatment) and homogenized (blending the creamy part with the skim part) it before packaging the milk for human consumption. This process has virtually eliminated milk borne illness in this country, but now certain farmers are threatening to reverse that progress.
So why are people fascinated with raw milk and seeking out farmers who will sell them milk prior to heat treatment? Raw milk does taste very good, and there’s no doubt that the creamy layer that floats on the top is delicious. In New York City raw milk has a black market, cult following. Should you jump on the bandwagon?
As my regular readers know, I grew up on an organic dairy farm, and had the pleasure of handling cows up close and personal for at least a decade. In fact, their sweet-smelling grass breath, and not so sweet-smelling cow patties are etched permanently in my mind. Cows are curious, somewhat dim witted, and generally oblivious to the terrain upon which they tread.
Cows will stand in manure for hours without a moment’s regret, should you present them with fresh hay to eat or some nice shortfeed. They drop patties on the ground, in their troughs, and occasionally on one other. Their flicking tails often get caked with manure as they swish flies away and they scratch their udders with dirty hooves as well.
This is why when it comes time to milk them, farmers need to wipe their udders carefully with a disinfectant scrub before applying the milk machine. Mastitis (or infection of the udder teets) is not uncommon, and is a reason for ceasing to milk a cow until the infection has cleared.
And so, the cleanliness of raw milk depends upon whether or not the farmer removes all the excrement carefully, scrubs the teets well, and remembers not to milk the cows with mastitits. It also matters whether or not the cows are harboring certain strains of bacteria – which often don’t harm the cow, but cause very serious problems for humans.
Did I drink raw milk as a kid? Occasionally, yes. Were my parents super-careful about the cleanliness of the milk? Yes. Did I ever get sick from raw milk? No. Would I give raw milk to my kids? No.
I appreciate that epicures want to experience the flavor of raw foods, but for me, the risks are simply not worth it when it comes to milk. There is no appreciable nutritional benefit to drinking raw milk (in fact, store bought milk is fortified with Vitamin D, which is critical for healthy bones), and it caries a small risk of serious infection. I agree with the FDA’s ban on interstate sales of unpasteurized milk, and would not want to see raw milk available widely for general consumption. Of course, to get around this ban, some companies are selling raw milk and cheese under the label “pet food.”
It’s a crazy country we live in – anti-bacterial hand wipes, soaps, gels, plastics and an insatiable appetite for raw milk. As a doctor, I throw up my hands. Is raw milk getting a raw deal? Some farmers may feel that way – but this former farmer is pleased to have access to safe, clean milk. What do you think?This post originally appeared on Dr. Val’s blog at RevolutionHealth.com.
I loved yogurt when yogurt wasn’t cool.
In fact, I grew up on a small dairy farm in Canada where our sole product was yogurt. My parents bought a cow (Daisy) “in an unguarded moment” and ended up having to get creative to get rid of all the extra milk that she produced for our family. One thing led to another – and I wound up as the VP of Sales and Marketing for a growing yogurt company taking Canada by storm. So when I saw today’s news release about Dannon being sued for exaggerated health claims for their yogurt, my dairy ears perked up.
First of all, if it’s true that Dannon is claiming that their yogurt has greater health benefits than other yogurts with active cultures, that’s false advertising.
I also think it’s pretty sneaky that they (allegedly) ran ad campaigns exaggerating the health benefits of yogurt, and then marked up their product by 30% to make consumers feel that they were getting added value from what was there all along. Typical big business move, right?
Secondly, yogurt bacteria do have beneficial uses (eating yogurt may decrease colon infection rates in hospitals, and can reduce the chance of vaginal yeast infections after antibiotic use). There is no conclusive evidence that yogurt treats or prevents diarrhea. However, it’s silly to extrapolate that these friendly bacteria will improve the health of your entire immune system – so you’ll never be sick – or that they will perfectly regulate your bowels – regardless of your underlying disease. As with many foods that have been shown to have some specific health benefits (green tea, blueberries, flax seeds) the media tends to blow them out of proportion.
And finally, what should you know about yogurt? Know that for those who are not allergic to milk products, it is a healthy nutritional option (especially the low fat variety without too much sugar) that may be especially important if you’re in the hospital or have received any antibiotics recently. Yogurt contains protein and calcium, which are important components of a healthy diet. But beyond this nutritional benefit (and the infection reduction in at-risk populations), I wouldn’t ascribe any particular magic powers to this tasty treat – as much as I’d like to.
1. Look for the “active cultures” sign on yogurt containers. The National Yogurt Association (NYA) established its own criteria for live and active culture yogurt in conjunction with its Live & Active Culture seal program. In order for manufacturers to carry the seal, refrigerated yogurt products must contain at least 100 million cultures per gram at the time of manufacture. Don’t pay extra for a yogurt because they have live cultures. The majority of them do!
2. Yogurt bacteria don’t live forever in your gut, so you’ll need to eat yogurt (or take active cultures) regularly to repopulate the colonies. I can’t find any data to support an exact consumption frequency. I guess it also depends on how many bacteria are contained in the yogurt or supplement you’re taking.
3. Acidophilus pills (one of the most popular yogurt bacterial strains) are available at health food stores for those who’d rather not eat yogurt but still want the benefits of the culture. These pills must be refrigerated to keep the culture alive (kind of like keeping milk cool) – and make sure you check the expiration date too. For more information on acidophilus, check out this supplement database.
4. The most common side effect of eating live yogurt cultures (in pill form or in yogurt form) is bloating and gas.
So don’t be surprised if you encounter it!
And I think that’s a nice thought to end on.This post originally appeared on Dr. Val’s blog at RevolutionHealth.com.